Running tools useful for installing lock mandrels and surface-controlled, wireline-retrievable safety valves in well bores are previously known. Difficulties have been experienced, however, when using conventional running tools that are piston sensitive to set lock mandrels and safety valves, especially in staggered bores. Such difficulties can arise where it is necessary to establish control line pressure to open the subsurface safety valve before the running tool can be released from the lock mandrel and withdrawn from the hole.
An improved running tool is needed that can install a lock mandrel and then be released without regard to the type or configuration of the tool, if any, being held by the lock mandrel. More particularly, a running tool is needed that can install an OTIS SAFETYSET lock mandrel in a staggered bore and then be released without establishing control line pressure.